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dc.contributor.advisorTomás Palacios.en_US
dc.contributor.authorMackin, Charles Edwarden_US
dc.contributor.otherMassachusetts Institute of Technology. Department of Electrical Engineering and Computer Science.en_US
dc.date.accessioned2018-09-17T15:57:18Z
dc.date.available2018-09-17T15:57:18Z
dc.date.copyright2018en_US
dc.date.issued2018en_US
dc.identifier.urihttp://hdl.handle.net/1721.1/118095
dc.descriptionThesis: Ph. D., Massachusetts Institute of Technology, Department of Electrical Engineering and Computer Science, 2018.en_US
dc.descriptionCataloged from PDF version of thesis. Page 199 blank.en_US
dc.descriptionIncludes bibliographical references (pages 173-198).en_US
dc.description.abstractGraphene exhibits a unique combination of properties making it particularly promising for sensing applications. This thesis builds new graphene chemical and biological sensing technologies from the ground up by developing device models, systems, and applications. On the modeling side, this thesis develops a DC model for graphene electrolyte-gated field-effect transistors (EGFETs). It also presents a novel frequency-dependent (AC) small-signal model for graphene EGFETs and demonstrates the ability of these devices to operate as functional amplifiers for the first time. Graphene sensors are transitioned to the system level by developing a new sensor array architecture in conjunction with a compact and easy-to-use custom data acquisition system. The system allows for simultaneous characterization of hundreds of sensors and provides insight into graphene EGFET performance variations. The system is adapted to develop solution-phase ionized calcium sensors using a graphene EGFET array that has been functionalized using a polyvinyl chloride (PVC) membrane containing a neutral calcium ionophore. Sensors are shown to accurately quantify ionized calcium over several orders of magnitude while exhibiting excellent selectivity, reversibility, response time, and a virtually ideal Nernstian response of 30.1 mV/decade. A new variation-insensitive distribution matching technique is also developed to enable faster readout. Finally, the sensor system is employed to develop gas-phase chemiresistive ammonia sensors that have been functionalized using cobalt porphyrin. Sensors provide enhanced sensitivity over pristine graphene while providing selectivity over interfering compounds such as water and common organic solvents. Sensor responses exhibit high correlation coefficients indicating consistent sensor response and reproducibility of the cobalt porphyrin functionalization. Variations in sensitivity follow a Gaussian distribution and are shown to stem from variations in the underlying sensor source-drain currents. A detailed kinetic model is developed describing sensor response profiles that incorporates two ammonia adsorption mechanisms--one reversible and one irreversible.en_US
dc.description.statementofresponsibilityby Charles Mackin.en_US
dc.format.extent199 pagesen_US
dc.language.isoengen_US
dc.publisherMassachusetts Institute of Technologyen_US
dc.rightsMIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.en_US
dc.rights.urihttp://dspace.mit.edu/handle/1721.1/7582en_US
dc.subjectElectrical Engineering and Computer Science.en_US
dc.titleGraphene chemical and biological sensors : modeling, systems, and applicationsen_US
dc.typeThesisen_US
dc.description.degreePh. D.en_US
dc.contributor.departmentMassachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
dc.identifier.oclc1052124112en_US


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